The aspects of the disclosed embodiments relate to an aircraft comprising stiffener edge junctions and to a method for producing one such aircraft. More specifically, the disclosed embodiments relate to a system for transmitting stresses at the intersection between a reinforcing frame and a stiffener in a fuselage and a method for producing one such system. The purpose of the disclosed embodiments is to route stresses efficiently between two consecutive sections of an aircraft's stiffener. Such a stiffener normally passes through a reinforcing frame in a fuselage of an aircraft. The disclosed embodiments also aim to allow for a simple production and installation of means for routing for stiffeners with an omega-shaped profile.
An aircraft's fuselage comprises several fuselage plated mounted together to form the fuselage. The fuselage plates have several stiffeners. The stiffeners are arranged in the form of raised ribs with respect to the said plates. The stiffeners extend over the plates, in the fuselage, along a longitudinal axis of the fuselage. In addition, such a fuselage includes reinforcing frames, particularly located at the junctions of the fuselage plates. These reinforcing plates are located perpendicularly along the longitudinal axis of the fuselage. In a fuselage, there are therefore many areas where the reinforcing frames and the stiffeners intersect.
At an intersection between a stiffener and a reinforcing frame, the stiffener is interrupted in order to give priority to the reinforcing frame. Such a stiffener is therefore arranged in the form of multiple stiffener sections. Said sections are aligned and separated from each other by the presence of reinforcing frames. However, in order to play its role correctly in the fuselage of a device, the stress that a stiffener endures must be transmitted from one stiffener section to another, despite the presence of interruptions.
It is known in the prior art, in the metal domain, to add brackets to the ends of the stiffener sections to allow continuity in the transmission of stress, despite the presence of reinforcing frames. Such brackets are supported on each side of the reinforcing frame and transmit stress from one stiffener section to the next section through the reinforcing frame, thereby ensuring a continuity of stress along a simple path.
However, such brackets are difficult to manufacture for a stiffener with an omega-shaped transverse profile. By an omega transversal profile, this means a stiffener having two sole plates extending parallel to the fuselage plates and continuously from the nearest ends of the two sole plates, with a stiffener head connecting these two sole plates together. Such a head is arranged in the form of a sail whose profile is trapezoidal or curved. In a transverse cross-section, both sole plates associated with the head give the stiffener a capital omega (Ω) shape.
In addition, the brackets cannot be produced entirely from composite materials. The presence of metallic elements is necessary for the production of the brackets. However, the presence of metallic elements causes corrosion problems, weight problems, and thermal problems in the fuselage.
It is also known from the prior art, in the metal and composite domains, to create double folds in the plate's skin. Such double folds help to increase the rigidity of the plate. The purpose of these folds is to transmit stress from one stiffener section to another, despite the presence of reinforcing frames. The skin covers the inner wall of the fuselage plates. Such folds are formed by creating an additional layer under the skin before the interruption of the stiffener. This additional layers drains stress from a stiffener section before the stiffener is interrupted and transmits it to the stiffener's next section. For this, a fold wing passes under the reinforcing frame and continues under the end of the following stiffener section to transmit stress effectively.
However, the presence of such fold wings under the stiffener implies a variation in the thickness of the skin where the stiffener is attached. It is difficult to produce a stiffener with an omega-shaped transverse profile that adapts to this variation in the thickness of the skin. In addition, the routing of stress from one stiffener section to another is complex, which results in a lower quality transmission of stress compared to the brackets.